Focus Points

• First-onset psychosis in a patient >30 years of age should alert the clinician to the possibility of organic psychosis.

• Dextromethorphan is a common ingredient in over-the-counter cough suppressants.

• When used in excessive amounts, dextromethorphan has the potential to induce bizarre feelings of dissociation, paranoia, and psychosis.

Abstract

This article presents a case of a 35-year-old woman presenting for the first time in a severely agitated, tearful, and psychotic state. She was experiencing frightening auditory hallucinations and was reading her Bible constantly throughout the night. She had been dancing around her house, going into the basement, and praying on her knees. She described how she “anointed her house with oil” by taking oil and painting a large cross on her bedroom wall. She had previously been a high functioning person, having some college education and having been employed in a bank for 7 years. She had no previous history of any psychiatric treatment or hospitalization. Upon physical examination, she presented with a severe cough and explained to the examiner that she had been using large quantities of Nyquil as a cough suppressant for days prior to admission. A diagnosis of dextromethorphan-induced psychosis was made. The patient responded well to risperidone 1 mg BID, sertraline 100 mg/day, and lorazepam 1 mg BID. Her psychosis resolved and she was discharged 1 week later. She returned to her job and there have been no further episodes of psychosis.

Introduction

This case report describes an unusual presentation of acute psychosis in a patient with no previous psychiatric history, who had been functioning at a high level as a bank employee. She presented in an agitated and paranoid state and had been behaving in a bizarre way at home for the past 2 days. There was no family history of any psychiatric illness nor history of head trauma or other medical problems other than an upper respiratory infection, for which she had been taking over-the-counter (OTC) cough suppressants. Upon obtaining further history, the patient had been ingesting large amounts of Nyquil, a common cough syrup containing dextromethorphan. Purposeful or accidental abuse of this agent has become a major societal concern because of its potential to induce a mind-altering state. This article discusses the metabolism of dextromethorphan as well as the psychiatric symptoms and physical signs accompanying its overdose. In any case of first-onset psychosis, all possibilities of potential organic causes should be exhaustively pursued in order to arrive at an accurate diagnosis and provide proper treatment. In as much as the association of schizophrenia with psychosis is such a common phenomenon, it is of particular importance that the clinician not be lulled into assuming that all psychosis is schizophrenia. This principle is emphasized in this case report.

Case Report

A 35-year-old female patient was brought to the emergency room by emergency medical services (EMS). According to the patient’s family, 2 days earlier she had been experiencing terrible nightmares which woke her throughout the night. The patient described how she saw the future in her dreams and would wake up terrified. She began to read her Bible all night and heard a voice which told her that terrible things would happen. Her family described how she would dance around the house and get down on her knees and pray in the basement. The patient herself said that she had “anointed [her] house with oil.” She described taking oil and painting a large cross on her bedroom wall. She said that she feared that demons were coming to get her. She left the house, went to a church, and said she thought she was going to a funeral. The patient was asked to leave the church and was brought back to her home, where her mother then called EMS.

Upon admission to the psychiatric unit, she was tearful, agitated, and extremely paranoid. Her verbal productivity was markedly diminished and she appeared frightened and guarded. Her behavior was bizarre. She could not remember anything that had happened to her prior to admission. She appeared to be responding to internal stimuli and was unable to verbalize her thoughts or feelings. She denied any suicidal ideation, although she was crying throughout the interview.

The patient is a high school graduate and had some college education. She had been working in a bank for 7 years. There is no history of alcohol or substance abuse. There was no previous history of any psychiatric treatment and no previous psychiatric hospitalizations. Social history revealed recent family stress. The patient has three children. She had recently been involved in an argument, precipitated by her children’s father, which resulted in police bringing charges against him. The patient had to appear in court and testify. As a result of the court decision, a personal protection order against him was issued. She had felt extremely stressed as a result of that experience, and was feeling depressed as well as physically and mentally exhausted.

This case presented a diagnostic challenge in as much as the patient presented with both depressive and psychotic symptoms, both of relatively recent onset, with no prior history of psychiatric illness. Physical examination and laboratory studies were all normal, with the exception of a low potassium level. All other laboratory studies were normal, as was a magnetic resonance imaging scan of the brain and chest x-ray.

Upon further questioning, the patient said that as a result of her physical exhaustion and lack of sleep she had developed an upper respiratory infection which had progressed to a severe cough. When asked what she had taken for her cough, she revealed that she had started taking Nyquil a few days before this recent event. She did not keep track of the dosage or how often she took it, but said she took it frequently throughout the days prior to her admission.

Initially, the patient was very paranoid and seclusive on the unit, choosing to remain isolated in her room and almost mute. She was too frightened to interact with patients or staff. She was started on risperidone 1 mg BID, sertraline 100 mg/day, and lorazepam 1 mg BID. The patient began to respond on the second day, with improvement in terms of verbalization, reality testing, and a decrease in paranoid delusional perceptions. She gradually became more cooperative, less suspicious, and was capable of participating in unit activities. A diagnosis of psychosis secondary to dextromethorphan overdose was made. The patient’s paranoia and psychosis completely cleared and she was discharged to outpatient therapy 1 week following admission.

Discussion

The active ingredient in Nyquil is dextromethorphan. This case illustrates the potential of OTC cough preparations to precipitate psychosis when used in greater than recommended amounts. Dextromethorphan, an antitussive agent, is an isomer of levomethorphan, a substance considered to be an opioid. It is rapidly absorbed from the gastrointestinal tract, enters the bloodstream, and crosses the blood-brain barrier. In the liver, dextromethorphan is metabolized by way of the cytochrome P450 2D6 pathway into its active metabolite dextrophan, the 3-hydroxy derivative of dextromethorphan.This is accomplished by O-demethylation, N-demethylation, and partial conjugation with glucuronic acid.

When consumed in large doses it can cause a buoyant psychedelic effect, but with higher doses, intense euphoria and vivid imagination may occur as bizarre feelings of dissociation increase. With even higher doses, profound alterations in consciousness, speeding up of sensory input, and frank psychosis has been documented. The psychosis is often accompanied by feelings of panic or dread. Commonly seen at high doses of dextromethorphan are symptoms of restlessness, misperception, and hallucinations, similar to the effects of the hallucinogenic agent phencyclidine. Psychological symptoms include altered sense of time, paranoia, and disorientation, as well as tactile, visual, and auditory hallucinations similar to the symptoms seen with phencyclidine.1 Price and Lebel2 described a patient who “believed he had died and become just his thoughts.” This same patient described vivid visual hallucinations, the ability to “see in all four quadrants,” delusions of telepathy, and paranoid thoughts that others wanted to kill him.

Because of its potential hallucinatory effect, OTC medications containing dextromethorphan have become a serious source for abuse.3 McFee and colleagues4 emphasized the euphoriant effect of dextromethorphan and describe the syndrome of altered mental state, ataxia, nystagmus, and seizures which might result. Because of its potential to induce altered states of consciousness, dextromethorphan has become a chronically addictive substance as well.5 Chronic users have described dose-dependent “plateaus” varying from mild stimulant effect with distorted visual perceptions at low doses to bizarre hallucinatory experiences, paranoia, and a sense of “complete dissociation from one’s body.” Cranston and Yoast6 emphasized the occurrence of altered time perception, paranoia, increased perceptual awareness, and visual hallucinations in patients with overdose of dextromethorphan. Schadel and Sellers7 reported a case of psychosis secondary to the abuse of another common OTC cough suppressant containing dextromethorphan. Sharma and colleagues8 reported a case of acute psychosis secondary to the use of Coricidin, a cough preparation containing dextromethorphan.

Physical symptoms of dextromethorphan overdose may include dilated pupils, urinary retention, elevated temperature, tachycardia, dizziness, vomiting, rash, and headache.9 Cases have been reported with severe overdoses in which there was lethargy, somnolence, ataxia, nystagmus, loss of consciousness, rigidity, and hypotension. Hinsberger and colleagues10 described toxic effects such as slurred speech, nausea, ataxia, nystagmus, mood changes, perceptual distortions, and aggressive behavior. Miller11 discussed the serotonergic properties of dextromethorphan, and its active metabolite dextrophan and stressed their ability to produce severe psychiatric sequelae and potentially life-threatening effects.

Conclusion

Although resembling a typical schizophrenic psychosis, overdose with dextromethorphan has unique accompanying physical signs and symptoms that should alert the examining physician. If level of consciousness and vital signs are stable, the patient can be treated with antipsychotics until the psychosis resolves. Blood studies should include serum dextromethorphan levels. In more serious cases, where loss of consciousness, hypotension, or arrhythmias may occur, more extreme measures must be taken such as administration of intravenous fluids, vasopressors, anti-arrhythmics, and naloxone. PP